Electronic control systems are used extensively in on-highway vehicles to perform a variety of operations. Some exemplary uses of electronic control systems include controlling transmission, cruise control, and/or anti-lock braking systems. As the use of these electronic control modules (or ECMs) increases, the level of complexity of communication between these systems and the vehicle also increases.
In order to deal with these increasingly complex communications, the Society of Automotive Engineers (SAE) has developed standards pertaining to the network of communications between electronic devices in vehicles. One of these standards is J1939. The J1939 standard specifies a high-speed communications network to support real-time closed loop control functions between ECMs, which may be physically distributed throughout the vehicle and may include a series of datalinks to each particular ECM.
A problem may arise when the datalink to a particular ECM becomes inoperative, or stops communicating. It is possible that the datalink may be inoperative without the vehicle's operator or a service technician knowing this. Because the operator or technician may be unaware that the vehicle failure is due to the datalink problem, the operator or technician may spend valuable time trouble-shooting the ECM or other vehicle systems to determine the cause of the vehicle behavior.
Systems currently exist that diagnose problems in electrical systems in vehicles. For example, U.S. Pat. No. 5,848,365, entitled “Diagnostic Method and System for Electrical System in a Truck” measures and stores voltages that are present on electrical connections during a time period prior to and after an event, such as an electrical fault. This system requires, however, that a technician have either knowledge of vehicle wiring and voltages, or conversely, have access to an external computer including diagnostic software. This system does not provide easy monitoring of the J1939 system in the field, nor does it provide for efficient repair of a problem.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.